Intervertebral Disc: Introduction Flashcards
What is the number of true intervertebral discs identified in the adult?
twenty three
What is the maximum number of common ligaments identified with a vertebral couple?
8
What is the reason that 9 common ligaments are identified but only 8 will be attached at any specific vertebral couple?
the ligamentum nuchae and supraspinous ligaments attach to the spinous tubercles, but only one of these will be identified at a single vertebral couple
In the adult, which vertebral levels will demonstrate a true intervertebral disc?
Those between C2 and S1 inclusive
What is the percent of intervertebral disc height contribution to the length of each region of the vertebral column?
Cervical 22-25%
Thoracic 20%
Lumbar 33%
What are the names of the central, peripheral, and horizontal zones of the intervertebral disc?
Nucleus pulposus…central zone; annulus fibrosus…peripheral zone; cartilaginous end plate…horizontal zone
What is the water concentration in the lumbar nucleus pulposus at birth and after thirty?
Birth 88%
Thirty 70%
What is the consequence of non-aggregated glycosaminoglycans in the lumbar nucleus puposus?
The nucleus pulposus will lose water under deformation conditions
What cell is associated with the nucleus pulposus until about age eleven?
Notochord Cells
Which type of collagen is dominant in the nucleus pulposus?
Collagen type II
What is the organizational pattern for collagen fibers in the nucleus pulposus?
They are irregularly oriented and randomly scattered
What is the appearance of the cervical annulus fibrosus?
A horse-shoe with the anterior margin thick and the lateral margins tapering to the uncinate processes; the posterior margin is thin
What compensates for the thinness of the posterior part of the cervical annulus fibrosus?
posterior longitudinal ligament
What is the organization of the lumbar annulus fibrosus?
It has 12-14 concentric cylindrical lamellae
What is the water concentration in the lumbar annulus fibrosus at birth and after thirty?
Birth 78%
Thirty 70%
What is the organizational pattern for glycosaminoglycans in the lumbar annulus fibrosus?
they typically have a binding site for hyaluronic acid and are thus aggregated
Which type of collagen is dominant in the annulus fibrosus?
Collagen Type I
What is the organizational pattern for collagen fibers in the annulus fibrosus?
they are parallel with one another in a single lamellus and angled
What is the organization of collagen fibers between lamellae?
collagen fibers will be angled in the opposite direction such that a spiral - counterspiral organization is observed
What is the attachment site for collagen fibers within the annulus fibrosus?
Collagen fibers of the outer lamellae will become Sharpey’s fibers and penetrate the epiphyseal rims; collagen fibers of the inner lamellae will attach to the cartilaginous end plate
What is the origin for the cells of the annulus fibrosus?
Sclerotomites
What is the principal type of collagen fiber within the cartilage end plate?
The type II Collagen fiber
What is the direction of collagen fibers within the cartilage end plate?
collagen fibers are aligned anterior to posterior
What is the attachment site for collagen fibers of the inner lamellae of the annulus fibrosus?
The cartilaginous end plate
